Skins,
Welcome to the site. I am happy to see another new collector with an M15 Baden Pickelhaube. I picked up my first Pickelhaube, a unit marked Baden M15, this past Fall and paid the same price but it didn't have the kokardes nor a repro chinstrap so barring any internal signs of your helmet being modified, it looks like you did fine. The unit marking on my Pickelhaube matches that of my P08 which is the reason that I became interested in acquiring it. If you provide a couple of clear pictures of the liner and the inside of the helmet, the experts here will be able to tell you a bit more. There are a multitude of nuances to this hobby and many on this site have spent the better part of their adult lives studying and collecting. Several have written authoritative books and articles so you have come to the right place. The Kaisersbunker site is another excellent resource which you should study.
Ricardo